1. Field of the Invention
This invention relates to dispensing valves and, more specifically, to a pressurized dispensing valve utilized in an extractor or the like.
2. Summary of the Prior Art
Dispensing of a solution from a closed tank, even from its bottom, requires a supply of air or other gas to the tank to prevent occurrence of a depressed pressure in the tank that retards or prevents flow from the tank. Because flow rate is a function of fluid depth, gravity alone will cause flow rate to approach zero as the tank nears empty. By applying pressure, a positive flow rate equal to or greater than a desired minimum value is assured. And by introducing the air from the bottom of the tank, you assure a more constant flow rate from full to empty.
If these two functions, gas delivery and fluid dispensing, were combined in one structure, savings such as the requirement for additional piping or the achievement of a more simple overall structure might occur.
Accordingly, it is an object of this invention to provide a combined dispensing and pressurizing valve.
It is an additional object of the invention to mount a valve within a valve to yield a pair of discrete flows.
It is an additional object of the invention to provide a composite valve structure having oppositely directed flows.
It is a further object of the invention to provide an easily mounted dispensing valve having a separate pressurizing source.
It is a still further object of the invention to provide a valve with an inner air passage surrounded by an outer fluid passage.
It is an even further object of the invention to provide an improved valve for dispensing fluids or the like.
It is an additional object of this invention to utilize an improved dispensing valve in an extractor or the like.